The objective of the present study is to establish the long-term response of the endogenous opiate system to surgical trauma and hemorrhagic shock and to relate plasma dynamics of beta-endorphin to changes that occur inplasma levels of adrenal hormones. To date, no studies have been performed which measure plasma concentrations of endogenous opiates during and following shock and trauma. Using rapid and multiple blood sampling techniques, we will measure plasma concentration of beta-endorphin, catecholamines and corticosteroids in female baboons subjected to 1) operative trauma of graded severity (5,10,15 minutes) or varying type (abdominal vs. thoracic) and 2) hemorrhagic shock. Blood samples will be collected continuously at hourly intervals over a two week post-trauma period in order to establish, for the first ime, the existence of plasma circadian rhythms of both catecholamines and beta-endorphin in the non-human primate and to correlate disruptions in the circadian rhythmicity of these hormones with trauma induced by surgical procedures or hemorrhagic shock. In addition, since recent studies have suggested that the endogenous opiate system contributes computerized hemodynamic monitoring will be performed associated with shock, concurrent computerized hemodynamic monitoring will be performed in order to quantitatively relate rapid endocrine changes to the cardiovascular alterations that may accompany shock and trauma. Finally, administration of opiate antagonists and/or corticosteroids will be performed in an effort to reverse the post-shock deterioration in cardiovascular function and disruption of plasma hormonal rhythms. These studies can be viewed as a step forward from the traditional analysis of changes in plasma levels of several hormones known to be secreted in response to shock trauma. By characterizing the plasma opiate response to surgical trauma and hemorrhage and correlating post-trama endorphin levels with plasma dynamics of adrenal hormones, we can develop a coherent view of how t hese systems may interact and contribute to the neuroendocrine response to trauma. In addition, the proposed pharmacological studies will help us determine whether or not the potential for improvement in the medical treatment of shock is possible.